Floridians along the Panhandle hunkered down Wednesday in preparation for an assault by a powerful Category 4 hurricane. Hurricane Michael, which on Tuesday had been projected to make landfall as a Category 3, grew in strength overnight as it fed off the warm coastal waters of the Gulf of Mexico. It is expected to make landfall Wednesday afternoon.

Assuming it maintains this strength, Michael will be the first Category 4 hurricane to hit the Florida Panhandle since records began in 1851, according to the Washington Post.

“The time for evacuating along the coast has come and gone,” Florida Gov. Rick Scott tweeted Wednesday morning. “First responders will not be able to come out in the middle of the storm. If you chose to stay in an evacuation zone, you must SEEK REFUGE IMMEDIATELY.”

The storm’s winds increased to nearly 145 miles per hour, according to the National Hurricane Center, and forecasters have warned residents of dangerous flash floods and deadly storm surges—in some areas as high as 13 feet, which would inundate coastal homes and possibly even wash some away, according to the National Weather Service.

Roads will likely become impassable, from downed trees, flooding, and debris. Forecasters expect widespread power outages in the region, and tornadoes could crop up across the panhandle.

Unlike Hurricane Florence, the storm will not linger but instead move rapidly up the coastline, sweeping through Georgia and the Carolinas on Thursday.

Florida, Georgia, and Alabama have all declared states of emergency, though only coastal areas in Florida have been ordered to evacuate. The weakened storm that moves off the coast looks to pose a particularly acute danger to the Carolinas, still waterlogged from Florence, as heavy rains and flash floods could ravage communities caught in the midst of rebuilding and recovery.

The storm could strengthen even more before it hits later in the afternoon.